Art of producing printed pictures in colors



Aug. 28, 1928. 1,681,927

L. W. BLISS ART OF PRODUCING PRINTED PICTURES IN COLORS Filed July 6, 1927' WIT/W586 INVENTOR WM LouxsYvLBhss,

c ATTORNEY Patented Aug. 28, 1928.

LOUIS W. BLISS, OF PATERSON. NEW JERSEY.

ART OF PRODUCING PRINTED PICTURES IN COLORS.

Application filed July 6, 1927. Serial No. 203,758.

WVhen a given picture in colors and shades of color is to be printed the usual practice is to separate photographically and with the use of color screens the primary colors in the original picture as prepared by hand by the artist and so that the resulting negatives will be adapted to produce half-tones and hence the graded effect in each color, and then by photo-engraving prepare separate printing surfacesfrom these negatives, one

for each of the primary colors, which surfaces, having applied the respective colors to them, are one after another applied to the paper or other surface to be printed 50 as to register and thus produce, compositely, the

picture. On account ofthe photographic color-separating step this procedure (known as process work) is exceedingly expensive, and there are other obstacles to such procedure where the matter of expense is a controlling factor, as that the half-tone effects -make necessary the use of a choice quality of paper on which the printing is done and the application in certain cases of certain special treatment of the printing surface before it can be used.

My principal object is to make it possible to print in any colors and shades of color without resort to photographical separation of the colors. To this end, the artist prepares by hand, in black, images of the respective areas to be occupied by the different. colors to be present in the ultimate picture; these images are then photomechanically reproduced all on the same scale on printing surfaces; then a printing substance is applied to each image-portion of each such printing surface in the color which appertains to that area which is the prototype of such imageportion; and finally said printing surfaces are applied to the surface on which the printing is to be done successively and in registry with each other.

The drawing shows a sheet of paper on which the artist has prepared by hand four images inblaek of the four color components of a picture to be used for advertisting (i. e., the three primary colors, red, blue and yellow, and a special color as gold, silver, etc. which I may remark in the present case plays no part in any color blending herein contemplated) and serves in illustrationof the preferred method of carrying out my invention, now to be describedin detail:

On a suitable surface, preferably a sheet of white paper, four separate fields, 2, 3, 4 and 5, as squares, are outlined in black. In each field is developed by the artist by hand, n black, its particular image hereinbefore indicated, as the images a, b, c and (Z in the respective fields 2, 3, 4 and 5, which are here the images of the red, blue, yellow and special-color areas, respectively, of the ultimate picture. This sheet of paper is then photographed so that the negative produced shall contain replicas of the four images, or four image-negatives in one. The black on the white produces a sharpness of contrast very important in order to obtain sharply defined results in the printing surfaces to be formed. Using this negative of the sheet and by photoengraving or equivalent photomechanical process, each unit is then reproduced on a plate or other body to form a printing surface.

Finally the image-portion of each printing surface has applied :thereto that particular color which appertains to that area which is a prototype (on the sheet of paper 1) of such image-portion, and the said printing surfaces are applied one after another to the paper or other surface to be printed, and of course in registry with each other, thus pro ducing the desired picture which the artist himself would have produced had he produced the picture complete.

I preferably not only photograph the sheet 1 intact upon preparing the images thereon but reproduce the printing surfaces from the negative of the sheet while preserving such negative intact. Thus I not only reduce handling and otherwise simplify the procedure but, what is almost invariably of vital importance in the ultimate picture, prevent any possibility of any image-portion on a printing surface departing from the proportion in point of size, or scale, of the original images; otherwise stated, conformity to the originally prescribed scale, being one of the factors in perfect registration in the print ing, is by this specific element of my invention positively assured. The printing plates or bodies on which the aforesaid image-portions are reproduced may be separate bodies properly assembled for the photo-mechanical pro notion of such image-portions with the aid of the (intact) negative, or they may be formed by a single plate or body which is later divided on lines corresponding to az-a: or y-y before use in printing.

While colors can be mixed together to produce other colors and shades of color, when they are superimposed on each other, as by successive applications of printing surfaces carrying different colors, the outer color frequently tends to conceal or suppress the inner or under color and so in such printing to prevent the production of certain colors and color efiects desired, this tendency becoming an actuality if the printing areas have portions appreciable in size which would print solid. So in such cases, instead of using solid black in the corresponding portions of sheet 1, the artist according to my invention resorts to lines, stippling, wash or other treatment which I herein term open-work (of course relying on his technique in the application of such open-work treatment so as to attain the shades and other effects he requires), so that the final printing surfaces shall be correspondingly of open-work character and hence not adapted to print the particular color for the area involved solid. An example is shown of such open-work treatment in the form of lines in the areas 0 (for yellow) and Z) (for blue) in images 0 and b for the top of the leaf there appearing; this will give a certain shade of green. The under side of the leaf is to have a darker shade of green wherefore the area I) alone is open-work, whereas the area 0 is left solid. Open-work is also shown at b, for example; here it happens to be stippling, assuming the artist, using his technique, believes such will produce a oer-- tain effect desired.

My procedure has another important advantage over the usual procedure first hereinbefore indicated in that in that case the half-tone effect will be present in the field around the object or shadows thereof pictured unless removed by a special or tooling treatment in order that the pictures may stand out sharply against its background, whereas by my invention this part of the field exists perfectly white and clear in the printed picture without special treatment.

In the claims I use the term colors in the general sense, or so as to comprehend shades as well as colors.

Preferably the artist prepares the ori inal images larger than they are intended to e in the finished picture, as 1 or 2 times larger, and in the step of forming the negative of the sheet 1 by photography the picture thus taken is reduced. This refines the technique of the artist and supresses any failure in registration which might otherwise be due tosome error of the artist in preparing the original lay-out of the images on sheet 1.

Having thusfully described my invention, what I claim is 1. The hereindescribed method of producing surfaces for printing a picture illustrative of objects appearing in several colors which consists in preparing, in separate fields of a single surface and in contrast therewith, original images of the respective areas to be occupied by the different colors to be present in such picture, then preparing a single photographic negative of all the images while preserving said surface intact, and then preparing the surfaces for the printing from such negative.

2. The hereindescribed method of producing surfaces for printing a picture illustrative of objects appearing in several colors which consists in preparing, in separate fields of a single surface and in contrast therewith, original images of the respective areasto be occupied by the different colors to be present in such picture, then preparing a single photographic negative of all the images while preserving said surface intact, and then preparing the surfaces for the printing from such negative while preserving the negative intact. Injtestimony whereof I aflix my signature.

LOUIS w. BLISS. 

